Joint sleeve for a rotor blade assembly of a wind turbine

ABSTRACT

A joint sleeve for assembling together a first blade section and a second blade section of a rotor blade assembly is disclosed. The joint sleeve may include an outer surface and an inner surface defining a cavity. The cavity may be configured to receive a joint end of the first blade section and a joint end of the second blade section. The joint sleeve may also include a plurality of openings defined between the outer and inner surfaces. The openings may be configured to receive fasteners for securing the joint ends of the first and second blade sections within the cavity. Additionally, a profile of the outer surface may be configured to generally correspond to an aerodynamic profile of the first and second blade sections such that a substantially continuous aerodynamic profile is defined between the first and second blade sections when the joint ends are inserted within the cavity.

FIELD OF THE INVENTION

The present subject matter relates generally to rotor blades of a windturbine and, more particularly, to a joint sleeve for joining bladesections of a rotor blade assembly.

BACKGROUND OF THE INVENTION

Wind power is considered one of the cleanest, most environmentallyfriendly energy sources presently available, and wind turbines havegained increased attention in this regard. A modern wind turbinetypically includes a tower, generator, gearbox, nacelle, and one or morerotor blades. The rotor blades capture kinetic energy from wind usingknown foil principles and transmit the kinetic energy through rotationalenergy to turn a shaft coupling the rotor blades to a gearbox, or if agearbox is not used, directly to the generator. The generator thenconverts the mechanical energy to electrical energy that may be deployedto a utility grid.

To ensure that wind power remains a viable energy source, efforts havebeen made to improve the overall performance of wind turbines bymodifying the size, shape and configuration of wind turbine rotorblades. One such modification has been to alter the configuration of thetip of the rotor blade. In particular, blade tips may be specificallydesigned to enhance or improve various aspects of a rotor blade'sperformance. For example, certain blade tips may be designed to operateefficiently in specific wind classes. Additionally, blade tips may beconfigured to enhance specific operating conditions of the wind turbine,such as by being configured to lower torque or reduce noise.

Thus, given that different operating advantages may be provided to awind turbine depending on the configuration of the blade tip, it wouldbe advantageous to have an attachment device that allowed for the quickand efficient assembly and disassembly of blade tips on and from a rotorblade. However, known attachment devices are typically complex and aremanually intensive to install. Additionally, such attachment devicesmake it difficult to accurately align the blade tip with the remainderof the rotor blade.

Accordingly, there is a need for a simple and efficient attachmentdevice for joining two blade sections of a rotor blade assembly.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in thefollowing description, or may be obvious from the description, or may belearned through practice of the invention.

In one aspect, the present subject matter discloses a rotor bladeassembly for a wind turbine. The rotor blade assembly generally includesa first blade section having a joint end and defining an aerodynamicprofile and a second blade section having a joint end and defining anaerodynamic profile. The rotor blade assembly also includes a jointsleeve having an inner surface and an outer surface. The inner surfacemay generally define a cavity configured to receive the joint ends ofthe first and second blade sections. Additionally, the rotor bladeassembly may include a plurality of fasteners configured to secure thejoint ends of the first and second blade sections within the cavity.Further, a profile of the outer surface of the joint sleeve maygenerally correspond to the aerodynamic profiles of the first and secondblade sections such that a substantially continuous aerodynamic profileis defined between the first and second blade sections when the jointends are inserted within the cavity.

In another aspect, the present subject matter discloses a joint sleevefor assembling together a first blade section and a second blade sectionof a rotor blade assembly. The joint sleeve may include an outer surfaceand an inner surface defining a cavity. The cavity may have a root endconfigured to receive a joint end of the first blade section and a tipend configured to receive a joint end of the second blade section. Thejoint sleeve may also include a plurality of openings defined betweenthe outer and inner surfaces. The openings may be configured to receivea plurality of fasteners for securing the joint ends of the first andsecond blade sections within the cavity. Additionally, a profile of theouter surface may be configured to generally correspond to anaerodynamic profile of the first and second blade sections such that asubstantially continuous aerodynamic profile is defined between thefirst and second blade sections when the joint ends are inserted withinthe cavity.

In a further aspect, the present subject matter discloses a tip assemblyfor a rotor blade of a wind turbine. The tip assembly may generallyinclude a joint sleeve having an inner surface defining a cavity and anouter surface defining an aerodynamic profile. The joint sleeve may alsoinclude a tip end and a root end. The tip assembly may also include atip section extending between a joint end disposed within the cavity anda blade tip. The tip section may define an aerodynamic profile generallycorresponding to the aerodynamic profile of the joint sleeve at the tipend. Additionally, tip assembly may include a plurality of fastenersconfigured to secure the joint end of the tip section within the cavity.Further, a portion of the cavity disposed at the root end of the jointsleeve may be configured to receive an end of a separate section of therotor blade.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with the description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures, in which:

FIG. 1 illustrates a perspective view of a wind turbine of conventionalconstruction;

FIG. 2 illustrates a perspective view of one embodiment of a rotor bladeassembly in accordance with aspects of the present subject matter;

FIG. 3 illustrates a partial, perspective view of the rotor bladeassembly shown in FIG. 2;

FIG. 4 illustrates a perspective view of one embodiment of a jointsleeve suitable for use with the disclosed rotor blade assembly inaccordance with aspects of the present subject matter;

FIG. 5 illustrates a partial, cross-sectional view of one embodiment ofthe attachment of several components of the disclosed rotor bladeassembly in accordance with aspects of the present subject matter;

FIG. 6 illustrates a partial, cross-sectional view of another embodimentof the attachment of several components of the disclosed rotor bladeassembly in accordance with aspects of the present subject matter; and,

FIG. 7 illustrates a perspective view of an embodiment of a tip assemblyin accordance with aspects of the present subject matter.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

In general, the present subject matter is directed to a joint sleeve forjoining together blades sections of a rotor blade assembly. Inparticular, the joint sleeve may define a cavity configured to receivean end of each blade section. For example, the cavity may generally havea shape corresponding to the shape of the ends of the blade sections,such as by having a tapered, aerodynamic profile corresponding to thetapered, aerodynamic profiles of the blade section ends. Suitablefasteners may then be inserted around the periphery of the joint sleeveto secure the ends of the blade sections within the cavity.

The disclosed joint sleeve may generally provide for the quick andefficient assembly and disassembly of a rotor blade. As such, a bladesection may be easily removed from and re-assembled onto the rotor bladefor purposes of maintenance, repairs and/or for upgrading theperformance of the rotor blade. For example, it may be preferable tovary the tip section of the rotor blade depending on the wind turbineoperating conditions and/or the desired performance of the rotor bladeassembly. Thus, by using the disclosed joint sleeve, tip sections havingdiffering dimensions, configurations and/or aerodynamic features may beefficiently assembled onto the rotor blade and/or replaced as desired.For example, a straight tip section (e.g., a tip section extending in asubstantially spanwise direction) may be replaced with a winglet-typetip section or vice versa. Similarly, a winglet having a particularconfiguration may be replaced with a winglet having a differentconfiguration.

Referring now to the drawings, FIG. 1 illustrates perspective view of awind turbine 10 of conventional construction. The wind turbine 10includes a tower 12 with a nacelle 14 mounted thereon. A plurality ofrotor blades 16 are mounted to a rotor hub 18, which is, in turn,connected to a main flange that turns a main rotor shaft. The windturbine power generation and control components are housed within thenacelle 14. It should be appreciated that the wind turbine 10 of FIG. 1is provided for illustrative purposes only to place the present subjectmatter in an exemplary field of use. Thus, one of ordinary skill in theart should readily appreciate that the scope of the present subjectmatter is not limited to any particular type of wind turbineconfiguration.

Referring now to FIGS. 2-4, embodiments of a rotor blade assembly 100and a joint sleeve 102 for joining together first and second bladesections 104, 106 of the rotor blade assembly 100 are illustrated inaccordance with aspects of the present subject matter. In particular,FIG. 2 illustrates a perspective view of one embodiment of the rotorblade assembly 100. FIG. 3 illustrates a partial, perspective view ofthe rotor blade assembly 100 illustrated in FIG. 2, particularlyillustrating the joint sleeve 102 disposed between the blade sections104, 106 of the rotor blade assembly 100. Additionally, FIG. 4illustrates a perspective view of one embodiment of the joint sleeve102.

As shown, the rotor blade assembly 100 includes a first blade section104, a second blade section 106 and a joint sleeve 102 configured tojoin the blade sections 104, 106 together. In general, the rotor bladeassembly 100 may be configured such that, when the first and secondblade sections 104, 106 are attached within the joint sleeve 102, acomplete rotor blade, defining a substantially aerodynamic profile, isformed. Thus, the complete rotor blade assembly 100 may generallyinclude a blade root 108 (defined by the first blade section 104)configured to be mounted to the hub 18 (FIG. 1) of a wind turbine 10 andblade tip 110 (defined by the second blade section 106) disposedopposite the blade root 108. The rotor blade assembly 100 may alsoinclude a span 112 defining the total length between the blade root 108and the blade tip 110 and a chord 114 defining the total length betweenthe leading edge 116 and the trailing edge 118. As is generallyunderstood, the chord 114 may vary in length with respect to the span112 as the rotor blade extends from the blade root 108 to the blade tip110.

In general, the first and second blade sections 104, 106 of the rotorblade assembly 100 may be configured similarly to any suitable bladesection and/or blade segment known in the art. For example, each bladesection 104, 106 may include a body shell 120 serving as the outercasing/covering of the blade section 104, 106 and one or more structuralcomponents (not shown) for providing stiffness and/or strength to theblade section 104, 106 (e.g., a shear web/spar cap assembly).Additionally, each blade section 104, 106 may generally define anaerodynamic profile. For instance, the body shells 120 of each bladesection 104, 106 may be configured to define an airfoil shapedcross-section, such as a symmetrical or cambered airfoil shapedcross-section. Thus, as shown in FIG. 3, each body shell 120 maygenerally define a pressure side 122, and a suction side 124 extendingbetween a leading edge 126 and trailing edge 128.

It should be appreciated that the body shells 120 may generally beformed from any suitable material. For instance, in one embodiment, eachbody shell 120 may be formed entirely from a laminate compositematerial, such as a carbon fiber-reinforced composite or a glassfiber-reinforced composite. Alternatively, one or more portions of eachbody shell 120 may be configured as a layered construction and mayinclude a core material, formed from a lightweight material such as wood(e.g., balsa), foam (extruded polystyrene foam) or a combination of suchmaterials, disposed between layers of laminate composite material.

Additionally, the first and second blade sections 104, 106 may eachinclude a joint end 130, 131 terminating within the joint sleeve 102.Thus, in the illustrated embodiment, the first blade section 104 maygenerally extend from the blade root 108 of the rotor blade assembly 100to its joint end 130 within the joint sleeve 102. Similarly, the secondblade section 102 may generally extend from its joint end 131 withinjoint sleeve 102 to the blade tip 110 of the rotor blade assembly 100.Further, as will be described in greater detail below with reference toFIGS. 5 and 6, the joint ends 130, 131 of the blade sections 104, 106may define a particular profile in order to facilitate insertion of thejoint ends 130, 131 within the joint sleeve 102. For instance, inseveral embodiments, the joint ends 130, 131 of each blade section 104,106 may define a tapered or stepped profile corresponding to a taperedor stepped profile defined in the joint sleeve 102.

Moreover, as shown in FIGS. 2 and 3, the first blade section 104 maygenerally extend lengthwise along a substantial portion of the span 112of the rotor blade assembly 100 such that the joint sleeve 102 isdisposed at an outboard position on the rotor blade generally proximateto the blade tip 110. As such, the second blade section 106 maygenerally be configured as an outboard or tip section of the rotor bladeassembly 100. Thus, in the illustrated embodiment, the second bladesection 106 may be configured similarly to the outboard portion of aconventional rotor blade 16 (FIG. 1), such as by extending in asubstantially spanwise direction between the joint end 131 of the bladesection 106 and the blade tip 110. Alternatively, as will describedbelow with reference to FIG. 7, the second blade section 106 may beconfigured as a winglet-type tip section or may otherwise have any othersuitable tip configuration know in the art.

It should be appreciated that, in embodiments in which the second bladesection 106 is configured as an outboard or tip section of the rotorblade assembly 100, the second blade section 106 may generally define arelatively short length 132. For example, in several embodiments, thesecond blade section 106 may define a length 132 which is less than 10meters (m) long, such as less than 5 m long or less than 3 m long andall other subranges therebetween. However, in alternative embodiments,the second blade section 106 need not be configured as a tip section ofthe rotor blade assembly 100 and, thus, may generally define anysuitable length 132, such as a length greater than or equal to 10 m. Insuch embodiments, it should be appreciated that the joint sleeve 102 maygenerally be disposed at any suitable location along the span 112 of therotor blade assembly 100, such as by being located at a more inboardposition closer to the blade root 108.

Still referring to FIGS. 2-4, the joint sleeve 102 of the disclosedrotor blade assembly 100 may generally be configured as an attachmentdevice for joining the first and second blade sections 104, 106. Thus,it should be appreciated that the joint sleeve 102 may generally haveany suitable configuration that permits the joint ends 130, 131 of theblade sections 104, 106 to be received within the joint sleeve 102. Forexample, in several embodiment, the joint sleeve 102 may have a hollowor a substantially hollow configuration for receiving the joint ends130, 131 of the blade sections 104, 106. In particular, as shown in FIG.4, the joint sleeve 102 may generally include an inner perimeter orinner surface 134 defining a cavity 136 extending between a root end 138and a tip end 140 of the joint sleeve 102. As such, the joint end 130 ofthe first blade section 104 may be configured to be received within theportion of the cavity 136 defined at the root end 138 of the jointsleeve 102 and the joint end 131 of the second blade section 106 may beconfigured to be received within the portion of the cavity 136 definedat the tip end 140 of the joint sleeve 102.

It should be appreciated that the joint ends 130, 131 of the bladesections 104, 106 may generally be attached within the cavity 136 of thejoint sleeve 102 using any suitable means. For example, in oneembodiment, the joint ends 130, 131 may be bonded within the jointsleeve 102 using any suitable adhesive. In another embodiment, aplurality of fasteners 142 may be utilized to secure the joint ends 130,131 within the joint sleeve 102. For example, as shown in FIGS. 3 and 4,the joint sleeve 102 may define a plurality of openings 144 extendingbetween its inner and outer surfaces 134, 146, with each opening 144being configured to receive a fastener 142. Specifically, a plurality ofopenings 144 may be defined proximate to the root end 138 of the jointsleeve 102 to permit a like number of fasteners 142 to be insertedthrough the openings 144 and attached to the joint end 130 of the firstblade section 104. Similarly, a plurality of openings 144 may be definedproximate the tip end 140 of the joint sleeve 102 to permit a likenumber of fasteners 142 to be inserted through the openings 144 andattached to the joint end 131 of the second blade section 106. It shouldbe readily appreciated that the openings 144 may be defined in the jointsleeve 102 so as to form any suitable bolt hole pattern. For example, inone embodiment, the openings 144 may form a single row along the rootand tips ends 138, 140 of the joint sleeve 102. In another embodiments,multiple rows (e.g., two or more rows) of openings 144, being aligned oroffset from one another, may be defined in the root and tip ends 138,140 of the joint sleeve 102.

It should also be appreciated that the fasteners 142 described hereinmay generally comprise any suitable fasteners known in the art. Forexample, in several embodiments, the fasteners 142 may be configured asthreaded fasteners, such as threaded bolts, screws and other suitablethreaded fastening devices. In other embodiments, the fasteners maycomprise other suitable fastening and/or attachment devices, such aspins, clips, brackets, rods, rivets, bonded fasteners and the like.

The disclosed joint sleeve 102 may also define a substantiallyaerodynamic profile. For example, as shown in FIG. 4, the joint sleeve102 may define an airfoil-shaped cross-section. Thus, similar to thefirst and second blade sections 104, 106, the outer surface 146 of thejoint sleeve 102 may generally define a pressure side 148 and a suctionside 150 extending between a leading edge 152 and a trailing edge 152.Additionally, in several embodiments of the present subject matter, theaerodynamic profile defined by the joint sleeve 102 may generallycorrespond to or otherwise match the aerodynamic profiles of the firstand second blade sections 104, 106. In particular, the aerodynamicprofile of the joint sleeve 102 at the root end 138 may generallycorrespond to the aerodynamic profile of the first blade section 102 inan area adjacent to its joint end 130. Similarly, the aerodynamicprofile of the joint sleeve 102 at the tip end 140 may generallycorrespond to the aerodynamic profile of the second blade section 106 inan area adjacent to its joint end 131. As such, when the blade sections104, 106 are assembled together within joint sleeve 102, the rotor bladeassembly 100 may generally define a substantially continuous aerodynamicprofile along its entire span 112. For instance, as shown in FIG. 3, thejoint sleeve 102 may be configured such that a substantially flush,aerodynamic surface is defined at the interface of the first bladesection 104 and the root end 138 of the joint sleeve 102 and at theinterface of the second blade section 106 and the tip end 140 of thejoint sleeve 102. Thus, the rotor blade assembly 100 may generallydefine a continuous aerodynamic surface between the first and secondblade sections 104, 106.

It should be appreciated that, in several embodiments, an additionalsurface feature may be applied to or positioned over the seams formed atthe interfaces of the blade sections 104, 106 and the ends 138, 140 ofthe joint sleeve 102 to ensure that a substantially smooth aerodynamicsurface is achieved. For example, in a particular embodiment, severalplies of a laminate composite material may be applied around the outerperimeter of the rotor blade assembly 100 at the joint seams, such as byusing a wet lay-up process, to provide a substantially flush aerodynamicsurface between the blade sections 104, 106 and the joint sleeve 102.

It should also be appreciated that the joint sleeve 102 may generally beformed from any suitable material. For example, in one embodiment, thejoint sleeve 102 may be formed from a metal, such as aluminum, steel andthe like. In other embodiments, the joint sleeve 102 may be formed froma laminate composite material, such as various fiber-reinforcedcomposites, or any other suitable non-metallic material.

Referring now to FIGS. 5 and 6, there is illustrated partial,cross-sectional views of two embodiments of the disclosed rotor bladeassembly 100, particularly illustrating the attachment of the first andsecond blade sections 104, 106 within the joint sleeve 102. As indicatedabove, the joint ends 130, 131 of the blade sections 104, 106 maygenerally be configured to be attached within the cavity 136 defined bythe joint sleeve 102 such that a substantially continuous aerodynamicprofile is defined along the span 112 (FIG. 2) of the rotor bladeassembly 100 and, particularly, at the interfaces between the root andtip ends 138, 140 of the joint sleeve 102 and the blade shells 120 ofthe blade sections 104, 106. Thus, in several embodiments, across-sectional height 156 of each blade section 104, 106 may generallybe reduced at the joint ends 130, 131 to permit the joint ends 130, 131to be inserted within the joint sleeve 102 and to ensure that asubstantially continuous or flush surface is defined between the bladesections 104, 106 and the joint sleeve 102.

For example, as shown in FIG. 5, in one embodiment, at least a portionof the joint ends 130, 131 of the blade sections 104, 106 may define atapered profile, such as by configuring the blade shells 120 to have atapered thickness 158, in order to permit the joint ends 130, 131 to bepositioned with the joint sleeve 102. Additionally, the joint sleeve 102may define a corresponding tapered profile so that the outer surface 146of the joint sleeve 102 is positioned substantially flush with the outersurfaces 160 of the blade shells 120. Thus, as shown, the joint sleeve102 may generally define tapered widths 162 at its root and tip ends138, 140 corresponding to the tapered thicknesses 158 of the bladeshells 120. It should be appreciated that, although the tapered widths162 of the joint sleeve 102 are shown as defining a substantially sharpor knife edge at the root and tip ends 138, 140, the tapered widths 162need not define such sharp or knife edges. For example, in oneembodiment, the tapered profile of the joint sleeve 102 may beconfigured to extend only partially along the tapered profiles of theblade sections 104, 106 such that relatively thin, blunt edges may bedefined at the root and tip ends 138, 140 of the joint sleeve 102. Insuch an embodiment, an additional surface feature, such as the laminateplies described above, may be applied at the root and tip ends 138, 140to ensure that a substantially continuous aerodynamic surface is definedbetween the blade sections 104, 106 and the joint sleeve 102.

Alternatively, as shown in FIG. 6, the joint ends 130, 131 of the bladesections 104, 106 may define a stepped profile, such as by configuringthe blade shells 120 to have a stepped reduction in thickness 164 at theroot and tip ends 138, 140 of the joint sleeve 102. In such anembodiment, the joint sleeve 102 may generally define a width 166substantially equal to the reduction in thickness defined in the bladeshells 120 so that the outer surface 146 of the joint sleeve 102 ispositioned substantially flush with the outer surfaces 160 of the bladeshells 120. In further embodiments, it should be appreciated that thejoint sleeve 102 and/or the joint ends 130, 131 of the blade sections104, 106 may generally have any other suitable configuration thatpermits the joint ends 130, 131 to be inserted within the joint sleeve102.

In general, the tapered or stepped profiles defined at the joint ends130, 131 of the blade sections 104, 106 may be formed using any suitablemeans. For example, in one embodiment, the tapered or stepped profilesmay be a molded feature of the blade shells 120, such as by creating amold having a tapered/stepped profile defined therein or by placing amold insert defining the tapered/stepped profile within the mold as theblade shells 120 are being formed. In another embodiment, the tapered orstepped profile may be machined into the blade shells 120 after theshells 120 have been formed, such as by using any suitable machiningprocess and/or any suitable machining equipment. Additionally, it shouldbe appreciated that the corresponding profile of the joint sleeve 102may generally be formed using any suitable means. For example, in oneembodiment, the joint sleeve 102 may be molded or otherwise formed toinclude the corresponding profile. In another embodiment, thecorresponding profile may be machined into the joint sleeve 102 usingany suitable machining process and/or any suitable machining equipment.

In a further embodiment of the present subject matter, one of thetapered or stepped profiles of the blade shells 120 or the correspondingprofile of the joint sleeve 102 may be initially formed and/or machinedand then scanned to permit the exact geometry of such profile(s) to beknown. For example, in one embodiment, a metrology or other 3-D scan maybe performed on the tapered profiles of the joint ends 130, 131 of eachblade section 104, 106. In such an embodiment, the tapered width 162 ofthe joint sleeve 102 may then be formed and/or machined based on thescan to ensure that the tapered width 162 corresponds the taperedprofiles of the blade sections 104, 106.

Referring still to FIGS. 5 and 6, in several embodiments, the openings144 defined in the joint sleeve 102 may include recessed features 170for recessing the fasteners 142 between the inner and outer surfaces134, 146 of the joint sleeve 102. In particular, the openings 144 may beconfigured such that the fasteners 142 are recessed partially or fullywithin the joint sleeve 102. For example, as shown in FIGS. 5 and 6, therecessed openings 144 may be configured such that the top surface 168 ofeach fastener 142 is positioned substantially flush with the outersurface 146 of the joint sleeve 102. As such, the joint sleeve 102 maygenerally define a substantially continuous aerodynamic profile betweenits root and tip ends 138, 140.

It should be appreciated that the size, shape and/or configuration ofthe recessed features 170 of the openings 144 may generally varydepending on the size, shape and/or configuration of the fasteners 142being used to attach the joint ends 130, 131 of the blade sections 104,106 within the joint sleeve 102. For example, as shown in FIG. 5, thefasteners 142 may generally comprise threaded fasteners having afastener head 172 defining a tapered diameter. In such an embodiment,the openings 144 formed in the joint sleeve 102 may generally define acorresponding tapered diameter such that the fastener head 172 may befully recessed within the joint sleeve 102. In another embodiment, shownin FIG. 6, the openings 144 may be configured as counterbored holeshaving a shape and/or configuration corresponding to the shape and/orconfiguration of the fastener head 172.

Referring still to FIGS. 5 and 6, to ensure proper attachment of theblade sections 104, 106 within the joint sleeve 102, the disclosed rotorblade assembly 100 may also include features for retaining the disclosedfasteners 142 within the joint ends 130, 131 of the blade sections 104,106. For example, in embodiments in which the fasteners 142 areconfigured as a threaded fasteners (e.g., threaded bolts), the rotorblade assembly 100 may include a plurality of female threaded members174 configured to receive the threaded fasteners 142 such that a clampedinterface is provided between the inner surface 134 of the joint sleeve102 and the joint ends 130, 131 of the blade sections 104, 106. Thus, asshown in FIGS. 5 and 6, a plurality of female threaded members 174 maybe configured to be aligned with the openings 144 defined in the jointsleeve 102 such that the fasteners 142 may be inserted through theopenings 144 and screwed into the threaded members 174. For instance, inthe embodiment shown in FIG. 5, the threaded members 174 may comprise aplurality threaded channels or plugs 176 configured to be mounted orotherwise disposed within the joint ends 130, 131 of the blade sections104, 106. In another embodiment, the threaded members 174 may comprise aplurality of nuts 178 mounted directly or indirectly to an inner surface182 of the blade shells 120. For example, as shown in FIG. 6, the nuts178 may be mounted onto a ganged channel or nut plate 180 extendingaround the inner perimeter of each blade shell 120. It should beappreciated that the nuts 178 may generally comprise any suitable nutknown in the art, including conventional, threaded nuts and floatingnuts. Additionally, in alternative embodiments, it should be appreciatedthat the threaded members 174 may have any other suitable configurationthat permits the fasteners 142 to be securely attached to the joint ends130, 131 of the first and second blade sections 104, 106.

In several embodiments of the present subject matter, the disclosedrotor blade assembly 100 may also include a divider 184 configured toseparate the joint end 130 of the first blade section 104 from the jointend 131 of the second blade section 106 within the joint sleeve 102. Thedivider 131 may also serve as a stop for locating or positioning thejoint ends 130, 131 of the blade sections 104, 106 within the jointsleeve 102. For example, in one embodiment, the divider 184 may bepositioned within the joint sleeve 102 such that, when the joint ends130, 131 of the blade sections 104, 106 are inserted fully within thejoint sleeve 102 and contact the divider 184, the threaded members 174disposed within or mounted to the blade shells 120 may generally bealigned with the openings 144 defined in the joint sleeve 102.

It should be appreciated that the divider 184 may generally have anysuitable configuration that permits the divider 184 to function asdescribed herein. For instance, as shown in FIGS. 5 and 6, the divider184 may be configured as a relatively thin member extending around theinner perimeter of the joint sleeve 102 substantially perpendicularly tothe inner surface 134. Additionally, as shown in FIG. 5, in oneembodiment, the divider 184 may extend inwardly from the inner surface134 only partially into the cavity 136 defined by the joint sleeve 102.Alternatively, as shown in FIG. 6, the divider 184 may be configured toextend from the inner surface 134 throughout the entire cavity 136 so asto divide the cavity 136 into two separate cavities.

Referring now to FIG. 7, there is illustrated a perspective view of atip assembly 200 in accordance with aspects of the present subjectmatter. In general, the tip assembly 200 may include a joint sleeve 202and a tip section 206. The joint sleeve 202 may generally be configuredsimilarly to the joint sleeve 102 described above with reference toFIGS. 2-6. Thus, the joint sleeve 202 may define a cavity 136 (FIG. 4)extending between a tip end 240 and a root end 238 of the joint sleeve202. The portion of the cavity 136 defined at the tip end 240 maygenerally be configured to receive a joint end 231 of the tip section206. For example, the joint sleeve 202 and the joint end 231 of the tipsection 206 may define corresponding tapered profiles such that thejoint end 231 may be inserted into the joint sleeve 202 and attachedtherein using a plurality of fasteners 242. Additionally, the jointsleeve 202 may define an aerodynamic profile generally corresponding tothe aerodynamic profile of the tip section 206. As such, when the tipsection 206 is inserted within the joint sleeve 202, the tip assembly200 may generally define a substantially continuous aerodynamic profilebetween the joint sleeve 202 and the tip section 206.

In general, the tip section 206 may extend from the joint end 231 to ablade tip 210 and may have any suitable tip configuration known in theart. For example, in one embodiment, the tip section 206 may beconfigured as a straight tip section, such as by being configuredsimilar to the second blade section 106 described above with referenceto FIGS. 2 and 3 and extending in a substantially spanwise directionbetween the joint end 231 and the blade tip 210. In another embodiment,shown in FIG. 7, the tip section 206 may be configured as a winglet-typetip section. As such, a winglet 290 may generally be defined between thejoint end 231 and the blade tip 210. It should be appreciated that thewinglet 290 may have any suitable configuration known in the art. Forexample, the winglet 290 may be configured as a suction side winglet oras a pressure side winglet. Additionally, the winglet 290 may define anysuitable sweep angle, cant angle, toe angle and/or twist angle, all ofwhich are commonly known terms in the aerodynamic art. Further, thewinglet 290 may define any suitable radius of curvature and may have anysuitable aspect ratio (i.e., ratio of the span of the winglet 290 to theplanform area of the winglet 290).

It should be appreciated that the disclosed tip assembly 200 maygenerally be configured as a replaceable tip for a rotor blade. Thus,the tip assembly 200 may be configured to be attached to any suitableinboard blade segment or section of a rotor blade. For example, theportion of the cavity 136 (FIG. 4) defined at the root end 238 of thejoint sleeve 202 may be configured to receive an end (not shown) of aninboard blade section (not shown), such as by being configured toreceive the joint end 130 of the first blade section 104 described abovewith references to FIGS. 2-6. Thus, in one embodiment, the end of theinboard blade section may be formed, machined or otherwise shaped so asto define a tapered profile corresponding to a tapered profile definedin the cavity 136 at the root end 238 such that the blade section may beinserted into the joint sleeve 202. Similar to the embodiments describedabove, the blade section may then be attached within the joint sleeve202 using a plurality of fasteners 242 inserted through the openings 244defined along the root end 238.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

1. A rotor blade assembly for a wind turbine, the rotor blade assemblycomprising: a first blade section including a joint end and defining anaerodynamic profile; a second blade section including a joint end anddefining an aerodynamic profile; a joint sleeve having an inner surfaceand an outer surface, the inner surface defining a cavity configured toreceive the joint ends of the first and second blade sections; and, aplurality of fasteners configured to secure the joint ends of the firstand second blade sections within the cavity, wherein a profile of theouter surface of the joint sleeve generally corresponds to theaerodynamic profiles of the first and second blade sections such that asubstantially continuous aerodynamic profile is defined between thefirst and second blade sections when the joint ends are inserted withinthe cavity.
 2. The rotor blade assembly of claim 1, wherein the secondblade section is configured as a tip section of the rotor bladeassembly.
 3. The rotor blade assembly of claim 2, wherein the tipsection defines a winglet.
 4. The rotor blade assembly of claim 1,wherein a tapered profile is defined at the joint ends of the first andsecond blade sections, the joint sleeve defining a tapered widthgenerally corresponding to the tapered profile.
 5. The rotor bladeassembly of claim 1, wherein a stepped profile is defined at the jointends of the first and second blade sections.
 6. The rotor blade assemblyof claim 1, wherein the plurality of fasteners comprises a plurality ofthreaded fasteners.
 7. The rotor blade assembly of claim 6, furthercomprising a plurality of threaded members disposed at the joint ends ofthe first and second blade sections, the plurality of threaded membersbeing configured to receive the plurality of threaded fasteners.
 8. Therotor blade assembly of claim 1, further comprising a plurality ofopenings defined between the inner and outer surfaces of the jointsleeve, each of the plurality of openings defining a recessed featureconfigured to recess the plurality of fasteners within the joint sleeve.9. The rotor blade assembly of claim 1, further comprising a dividerconfigured to separate the joint ends of the first and second bladesections within the cavity.
 10. A joint sleeve for assembling together afirst blade section and a second blade section of a rotor bladeassembly, the sleeve comprising: an outer surface; an inner surfacedefining a cavity, the cavity having a root end configured to receive ajoint end of the first blade section and a tip end configured to receivea joint end of the second blade section; and, a plurality of openingsdefined between the outer and inner surfaces, the plurality of openingsbeing configured to receive a plurality of fasteners for securing thejoint ends of the first and second blade sections within the cavity,wherein a profile of the outer surface is configured to generallycorrespond to an aerodynamic profile of the first and second bladesections such that a substantially continuous aerodynamic profile isdefined between the first and second blade sections when the joint endsare inserted within the cavity.
 11. The joint sleeve of claim 10,wherein a tapered width is defined between the outer and inner surfaces.12. The joint sleeve of claim 10, wherein each of the plurality ofopenings defines a recessed feature between the outer and innersurfaces.
 13. The joint sleeve of claim 10, further comprising a dividerconfigured to separate the joint ends of the first and second bladesections within the cavity.
 14. The joint sleeve of claim 10, whereinthe divider extends substantially perpendicularly from the innersurface.
 15. The joint sleeve of claim 10, wherein an aerodynamicprofile of the root end generally corresponds to the aerodynamic profileof the first blade section and an aerodynamic profile of the tip endgenerally corresponds to the aerodynamic profile of the second bladesection.
 16. A tip assembly for a rotor blade of a wind turbine, the tipassembly comprising: a joint sleeve including an inner surface defininga cavity and an outer surface defining an aerodynamic profile, the jointsleeve further including a tip end and a root end, a tip sectionextending between a joint end and a blade tip and defining anaerodynamic profile generally corresponding to the aerodynamic profileof the joint sleeve at the tip end, the joint end of the tip sectionbeing disposed within the cavity; and, a plurality of fastenersconfigured to secure the joint end of the tip section within the cavity,wherein a portion of the cavity disposed at the root end of the jointsleeve is configured to receive an end of a separate section of therotor blade.
 17. The tip assembly of claim 16, wherein the tip sectiondefines a winglet.
 18. The tip assembly of claim 16, wherein a taperedprofile is defined at the joint end of the tip section, the joint sleevedefining a tapered width generally corresponding to the tapered profile.19. The tip assembly of claim 16, further comprising a plurality ofopenings defined along the tip end of the joint sleeve and configured toreceive the plurality of fasteners, each of the plurality of openingsdefining a recessed feature configured to recess the plurality offasteners within the joint sleeve.
 20. The tip assembly of claim 16,further comprising a plurality of openings defined along the root end ofthe joint sleeve, the plurality of openings being configured to receivea plurality of fasteners for securing the end of the separate section ofthe rotor blade within the cavity.